I’m 99% this is a bug. Just follow the steps:

1- Set system unit setup to “inches”.
2- Create a sphere
3- Apply a Hair and Fur modifier
4- Create a Spotlight to illuminate the hair and turn cast shadows on.
5- Render…
6- Now set system unit setup to millimeters and render again.

The hair is black. It happens in max 2008/2009 and 2009 sp1...I tested in max 8 and works fine. The shadows that are causing problems as I can see. Hair is not scene scale dependent AFAIK…

And I thought in max 2009 they had enhanced Hair and Fur…

Regards,

Jr.

(From the Help on System Units - in both Max 8 and Max 2009)

Warning You should only change the system unit value before importing or creating geometry. Do not change the system unit in an existing scene.

Might be a little unfair calling that a bug having just done something they warn you not to do. Try “Rescale World Units” (25.4 to keep the sphere the same “actual” size) and see if that cures it. No guarantees, just a suggestion.

Max 4.2 through 2013.
XP-64 (SP2)
NVidia 9800GTX-512 (Driver 266.58).
Core 2 Quad Q6600 2.4GHz, 8Gb Ram, DX9.0c.

Thanks for the input Steve.

But that’s a different matter to me, what the warning wants to prevent is because changing that can break so many things apart, since it’s effectively changing the scale of everything. Every dynamic simulation, lights (with decay), shader, and especially rigs will just become a huge pile of trash. That’s a very generic warning…

As far as I know, hair is not scene scale dependent, I just tested it in max 8 and i worked like expected, so it should in max 2008 / 2009. I said to change the scene scale on the fly to be easier to understand and see the problem, because if you start in millimeters from the scratch it will not work either.

Anyway, in my case here, it’s waaaay too dangerous to change the scene scale of my scenes. It’s not just for a file, but for a whole pipeline that was already setup in millimeters, before it to be my responsibility. If it was on my hands from the very beginning, I wouldn’t do that, as I know that soon or later it will cause problems (I always work in inches and set display units to what I want). But it wasn’t, and now here I am…

I still think it’s a but…

Regards,

Jr.

If you can create a simple scene in Max 8, with Hair and Fur, and it works, and you then load that scene into 2008/2009 and it doesn’t then I’d agree with you that it’s a bug. Always best to keep it simple if you’re going to use it as the basis of a bug report.

I’m not quite sure how you’re going to address the scale issue if it’s part of your pipeline. Need input from others who have to contend with similar issues.

Max 4.2 through 2013.
XP-64 (SP2)
NVidia 9800GTX-512 (Driver 266.58).
Core 2 Quad Q6600 2.4GHz, 8Gb Ram, DX9.0c.

Well, I’ll say one thing. Hair and Fur is enhanced in every release, it follows the upgrade path of Shave and Haircut, except that it is a couple releases behind, so the Hair and fur in Max 2009 is like Shave and Haircut in 2007.

-Austin: Using Maya 2009
My CGSociety Portfolio
IRC Nick: AustinZ

After some testing, I can indeed say it’s a scaling issue most prevalent in the conversion from SUinches to SUmillimeters. Other conversions had no noticeable issues (ie in-->cm, in-->m, etc.) For this specific problem (as in this thread and setup) when changing SU from in to mm - set 1 unit = 20 mm (or whatever an inch is..22 something) and the “bug” is gone.

I don’t know how this relates to your actual situation (if any) but it worked here.
Hope this helps. Max2009sp1 btw.

MP

Max 2009, 2010 32/64
VistaP 64 SP1
Intel Q9550 8GB
ATI 4870x2
Patriot 128GB SSD

Warning You should only change the system unit value before importing or creating geometry. Do not change the system unit in an existing scene.

I tried it the other way around, the first thing I did was change the units from cm (my maxstart defaults to cm) to mm and then made the sphere, hair and spot light. The hair renders black.

uuahh…

guys I do have the same issue.. my worklfow is based on mm… my whole scene setup is based on that, and I do have aleady tones of work done in mm. I have a character, fully rigged and skinned, dynamics with reactor, cloth and even particles…

all is setup and ready to go, but the hair does not work with mm....

I tried to change the US from mm to Centimer, just to see how it will effect the hair.
but there was nothing that has changed.

I really appreciate every little input and help how I can get now my hair done.

thx a lot,
bernhard

I would imagine that is a different issue. I work in mm, and have never had a problem with hair (not that I use it much, but...).  Are you saying that in a new scene, with mm system units, you can’t create hair? Do you have a test scene you could post? Are you using MR or Scanline?

MP

Max 2009, 2010 32/64
VistaP 64 SP1
Intel Q9550 8GB
ATI 4870x2
Patriot 128GB SSD

Hello,

I mean you can create hair in mm, but you will run into issues, in my case render issues…
the hair looks really different in mm, with the same preset or hair setup, and of course smae lighting setup.

I used straight scnaline, tested also mr and vray.
but I only can agree to the comments above....

I switched now to centimeter and kabumm.. like magic, it’s different.

now I have realized the first issue with hair, I am comming to the second one:

I realized that the hair effect render, can’t handle opacity maps.
So I switched to the G-Buffer, because the G-Buffer can handle.

But for some reason, I have now a kind of antialiasing problem.
What does it mean…

the hair looks on the outlines (where it collides with the head) very fuzzy… the edges look like an AA issue.

Can’t really say..  I tried to fix that with different render settings, but couldn’t fix it.

After that, I tried the collission object, because my hair needs to be animated on a character.
And this is issue three… the hair doesn’t really collide with the head’s mehs, if I just use the collission parameter inside the Hair Modifier.

lol.. wonderful.... this tool really creates problems, and problems…

so to solve issue three, I guess I need to use maybe the cloth modifier, run a simulation with kind of hair poly objects, and after skinwrap the spline hair.

well… well… this hair tool can cost you at least some grey hair.... lol:

all the best,
bernhard